In general, a refrigerator is an apparatus that stores objects in a fresh state for a long period of time using cool air supplied into a storage compartment. The cool air supplied into the storage compartment is generated through heat exchange of a refrigerant. The cool air supplied into the storage compartment is uniformly distributed in the storage compartment by convection to store foods at desired temperature.
Such a refrigerator may be constructed not only such that a freezing compartment and a refrigerating compartment are cooled by a single evaporator but also such that a freezing compartment and a refrigerating compartment are cooled by a freezing compartment evaporator and a refrigerating compartment evaporator, respectively.
Particularly, as a conventional method of controlling a refrigerator, there is proposed a method designed to alternately cool a refrigerating compartment and a freezing compartment using one compressor and two evaporators by means of a changeover valve.
However, the conventional method has problems in that it is difficult to achieve rapid cooling when the changeover valve is alternately opened toward the two evaporators during initial start-up of the compressor and that cooling of a refrigerating compartment is excessively delayed when cooling is initiated from a freezing compartment during the initial start-up of the compressor.
Furthermore, although it is necessary to provide rapid cooling when a temperature of one of a freezing compartment and a refrigerating compartment is excessively increased, the rapid cooling cannot be easily achieved.